COUNTY · CA
Marin County, California
Marin County is a county in California with FIPS code 06041 and an estimated population of 254,407 (Census 2023), 26th largest of 58 in the state.
County facts
- Name
- Marin County
- State
- California
- Type
- county
- FIPS code
- 06041
- State FIPS
- 06
- Population (2023)
- 254,407
- Change since 2020
- -2.6%
- State rank
- 26 of 58
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Marin County?
Marin County, California has the five-digit FIPS code 06041: 06 for the state and 041 for the county.
What state is Marin County in?
Marin County is in California.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.